birth defect

birth defect Any defect present in a baby at birth. Birth defects involve many different tissues, including the brain, heart, lungs, liver, bones, and intestinal tract. These defects can occur for many reasons, including genetic conditions and toxic exposures of the fetus (for example, to alcohol). All parents are at risk of having a baby with a birth defect. Birth defects are now the leading cause of infant mortality (death) in the US and many other developed nations. Infrequent, but significant, birth defects include heart defects, cleft lip and palate, Down syndrome, and spina bifida. Also known as congenital malformation or congenital anomaly. See also dysmorphology.